When a payslip is confirmed in Odoo (in the presence of the hr_payroll_account module), Odoo can generate analytic accounting entries corresponding to each salary line. These entries are used to allocate payroll costs to analytic accounts that typically represent departments, projects, or cost centers.

Analytic Accounts must be configured either:

• On the Salary Rule (analytic_account_id or analytic_distribution), or
• On the Employee’s Contract (analytic_account_id as fallback).

Odoo uses the following logic per salary line to determine the analytic allocation:

1. If the Salary Rule has an analytic account (or distribution), it is used.
2. Otherwise, if the Contract has an analytic account, that is used.
3. If neither is set, no analytic entry is created for that salary line.